"Washboard" effect or look on some Curly Maple stocks

[Blackpowder Barbie]

It is my understanding of the biology side of wood, that it takes approximately 200 or so years for a tree to completely die.  Meaning for the cells to loose all ability to maintain moisture and thus stop moving.  So even if you start with a piece of kiln dried wood and have it smooth as glass in 15-20 years the cells have degraded enough to cause it to washboard.  Thus why so many originals we see look like that.  One of Dad's rifles that he made back in 1983 was completely smooth to the touch then, but now has slight ripples. 

[Dr. Tim-Boone]

SSHHHH don't tell him thqat !!  It will make him feel old... 

[bama]

The last red maple stocked rifle I finished had a scraped finish and it had this washboard effect. I also think that wear and drying have and effect also. The Sheetz styled rifle I am finishing up is a hard sugar maple stock and in one area of the wrist it has this rippled effect from the scraped finish. The balance of the stock is fairly smooth. So I think a scraped finish is the main culprit. With that said not all my scraped guns have the ripple or wash board effet. I think it has a lot to do with the piece of wood. I also agree with Jim that it happens more on the quarter sawn than the slab sawn.